Wow, an interesting discussion here! I thought the original post was pretty insightful, but disagree with some of the further discussion.

Utilitarian philosophy is the only one I know of that arises from scientific thinking. I'd recommend reading up on it to see some interesting exploration of these issues. What follows isn't necessarily a description of that philosophy, but my interpretation of how that kind of thinking would be applied to this discussion.

Knowledge is gained through the scientific method (and that includes knowledge of social issues as well... not just physics, biology, etc...) But as was said earlier, knowledge alone isn't enough to make a decision. Any choice requires having a goal in mind. What is the desired outcome? What is the perfect state that we wish to approach?

Knowledge, gathered through the scientific method, can give us the most likely result of any given action. Therefore, if there is a place for what you call "wisdom" I think it has to be in determining what that perfect state is that we're trying to reach. The unfortunate thing (which is why I agreed with the initial post) is that people's interests will always be divergent. A gain for one usually means a loss for another. Balancing divergent interests is difficult, but if there truly is some ideal that we are trying to reach, one option will usually get us closer than the other.

The point is that while we definitely have to accept the fact that we will never be able to get everything we want, there are ways to make decisions in a scientific way such that we know we are going in the direction we want to go (to the best of our knowledge). This method does not allow for dogmatic thinking and doesn't lend itself to soundbites, though, so I don't see many politicians adopting it any time soon.